Most pairs of polymers are immiscible in one another. This is a direct consequence of their macromolecular nature. Since there is a strong commercial incentive to make useful materials from mixtures of various polymers, there has been a great deal of activity in the area of improving the compatibility of such immiscible, multiphase systems. For example, blends of different polyolefins are made in many different combinations and compositions with the use of compatibilizers. Although in principle graft and block copolymers made by a variety of techniques are useful as compatibilizers, graft copolymers are most commonly used, in part, because true block copolymer presently exist for only a small number of the possible pairs of monomers. Consequently, for most blends there is no corresponding true block copolymer that might be useful as a compatibilizer. Also, experience has shown that many block copolymers display low levels of compatibilizing efficiency.
The use of ethylene-alpha olefin copolymers to compatibilize polyethylene and poly alphaolefin homopolymers is known in the art. However, these copolymers have isotactic poly alphaolefin segments such as isotactic polypropylene. Consequently, there is a need for copolymer compatibilizers of polyethylene and atactic poly alpha-olefins.